Related Clues:

• Backup groups, often
• The Supremes and others
• Jazz ensembles
• Some folk groups
• Small chamber groups
• Some chamber music groups
• Tuneful threesomes
• Some Beethoven works
• The Ghostbusters and the Police
• Cabaret lineup
• Some jazz groups
• ZZ Top and Cream
• Small music groups
• Small pop groups
• Bands of three